We came across this article and it appears it might be of benefit to many of our clients. The Boats US Foundation has awarded over $250,000 in grants to improve water quality. This year they are focusing on invasive species according to this article. Groups can apply for and receive up to $4,000 to do projects that would stop the spread of plants like Eurasian Milfoil. The article here explains this and has a link to their site to get an application. Applications are due by February 1, 2008. Good Luck!
A direct link to this program is http://www.boatus.com/foundation/cleanwater/grants/